[PATCH V3 2/5] PCI: dwc: Refactor core initialization code for EP mode

[Vidya Sagar]

Splits core initialization code for EP mode into two, one that doesn't
touch core registers and the other that touches core registers. The latter
would be called/skipped based on the EPC feature 'core_init_notifier'.
In case of platforms where this is skipped (Ex:- Tegra194), it would be
called indirectly through hooks from the function driver.

Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
Acked-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---
V3:
* Added Acked-by: Kishon Vijay Abraham I <kishon@xxxxxx>

V2:
* Changed EPC feature name from 'skip_core_init' to 'core_init_notifier'
* Made the pci-epc.h header file change as a separate patch as per the review
  comment from Kishon

 .../pci/controller/dwc/pcie-designware-ep.c   | 72 +++++++++++--------
 drivers/pci/controller/dwc/pcie-designware.h  |  6 ++
 2 files changed, 50 insertions(+), 28 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index cfeccd7e9fff..84a102df9f62 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -492,19 +492,53 @@ static unsigned int dw_pcie_ep_find_ext_capability(struct dw_pcie *pci, int cap)
 	return 0;
 }
 
-int dw_pcie_ep_init(struct dw_pcie_ep *ep)
+int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
 {
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	unsigned int offset;
+	unsigned int nbars;
+	u8 hdr_type;
+	u32 reg;
 	int i;
+
+	hdr_type = dw_pcie_readb_dbi(pci, PCI_HEADER_TYPE);
+	if (hdr_type != PCI_HEADER_TYPE_NORMAL) {
+		dev_err(pci->dev,
+			"PCIe controller is not set to EP mode (hdr_type:0x%x)!\n",
+			hdr_type);
+		return -EIO;
+	}
+
+	ep->msi_cap = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
+
+	ep->msix_cap = dw_pcie_find_capability(pci, PCI_CAP_ID_MSIX);
+
+	offset = dw_pcie_ep_find_ext_capability(pci, PCI_EXT_CAP_ID_REBAR);
+	if (offset) {
+		reg = dw_pcie_readl_dbi(pci, offset + PCI_REBAR_CTRL);
+		nbars = (reg & PCI_REBAR_CTRL_NBAR_MASK) >>
+			PCI_REBAR_CTRL_NBAR_SHIFT;
+
+		dw_pcie_dbi_ro_wr_en(pci);
+		for (i = 0; i < nbars; i++, offset += PCI_REBAR_CTRL)
+			dw_pcie_writel_dbi(pci, offset + PCI_REBAR_CAP, 0x0);
+		dw_pcie_dbi_ro_wr_dis(pci);
+	}
+
+	dw_pcie_setup(pci);
+
+	return 0;
+}
+
+int dw_pcie_ep_init(struct dw_pcie_ep *ep)
+{
 	int ret;
-	u32 reg;
 	void *addr;
-	u8 hdr_type;
-	unsigned int nbars;
-	unsigned int offset;
 	struct pci_epc *epc;
 	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
 	struct device *dev = pci->dev;
 	struct device_node *np = dev->of_node;
+	const struct pci_epc_features *epc_features;
 
 	if (!pci->dbi_base || !pci->dbi_base2) {
 		dev_err(dev, "dbi_base/dbi_base2 is not populated\n");
@@ -563,13 +597,6 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 	if (ep->ops->ep_init)
 		ep->ops->ep_init(ep);
 
-	hdr_type = dw_pcie_readb_dbi(pci, PCI_HEADER_TYPE);
-	if (hdr_type != PCI_HEADER_TYPE_NORMAL) {
-		dev_err(pci->dev, "PCIe controller is not set to EP mode (hdr_type:0x%x)!\n",
-			hdr_type);
-		return -EIO;
-	}
-
 	ret = of_property_read_u8(np, "max-functions", &epc->max_functions);
 	if (ret < 0)
 		epc->max_functions = 1;
@@ -587,23 +614,12 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 		dev_err(dev, "Failed to reserve memory for MSI/MSI-X\n");
 		return -ENOMEM;
 	}
-	ep->msi_cap = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
 
-	ep->msix_cap = dw_pcie_find_capability(pci, PCI_CAP_ID_MSIX);
-
-	offset = dw_pcie_ep_find_ext_capability(pci, PCI_EXT_CAP_ID_REBAR);
-	if (offset) {
-		reg = dw_pcie_readl_dbi(pci, offset + PCI_REBAR_CTRL);
-		nbars = (reg & PCI_REBAR_CTRL_NBAR_MASK) >>
-			PCI_REBAR_CTRL_NBAR_SHIFT;
-
-		dw_pcie_dbi_ro_wr_en(pci);
-		for (i = 0; i < nbars; i++, offset += PCI_REBAR_CTRL)
-			dw_pcie_writel_dbi(pci, offset + PCI_REBAR_CAP, 0x0);
-		dw_pcie_dbi_ro_wr_dis(pci);
+	if (ep->ops->get_features) {
+		epc_features = ep->ops->get_features(ep);
+		if (epc_features->core_init_notifier)
+			return 0;
 	}
 
-	dw_pcie_setup(pci);
-
-	return 0;
+	return dw_pcie_ep_init_complete(ep);
 }
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index a22ea5982817..b67b7f756bc2 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -411,6 +411,7 @@ static inline int dw_pcie_allocate_domains(struct pcie_port *pp)
 #ifdef CONFIG_PCIE_DW_EP
 void dw_pcie_ep_linkup(struct dw_pcie_ep *ep);
 int dw_pcie_ep_init(struct dw_pcie_ep *ep);
+int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep);
 void dw_pcie_ep_exit(struct dw_pcie_ep *ep);
 int dw_pcie_ep_raise_legacy_irq(struct dw_pcie_ep *ep, u8 func_no);
 int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
@@ -428,6 +429,11 @@ static inline int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 	return 0;
 }
 
+static inline int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
+{
+	return 0;
+}
+
 static inline void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
 {
 }
-- 
2.17.1